Phenol, also known as carbolic acid or phenic acid, is an organic compound with the chemical formula C₆H₅OH. In its pure form, phenol appears as white or clear needle-like crystals. It solidifies at around 41°C and can be liquefied by adding a small amount of water (2 parts water to 23 parts phenol). When exposed to air and light, phenol tends to discolour, turning pink or red—a process accelerated by impurities or alkaline substances.
Phenol has a distinct sweet, medicinal, or tar-like odour. It is mildly acidic but must be handled with care due to its corrosive nature and potential to cause burns. Historically extracted from coal tar, phenol is now produced on a large industrial scale—approximately 7 billion kg annually—primarily derived from crude oil.
Phenol serves as a general disinfectant and a chemical reagent in various processes. It plays a key role in manufacturing artificial resins, pharmaceuticals, dyes, and organic compounds used in both medical and industrial applications. Additional uses include the production of:
The largest application of phenol is in the production of phenolic resins, which are used in adhesives for plywood, construction materials, automotive parts, and household appliances. It is also an intermediate in the manufacture of caprolactam (used to produce nylon) and bisphenol A (used in epoxy and other resins).
Phenol is found in oil refinery waste, as well as in the by-products of coal gasification and metallurgical coke production. It may be released into the environment through discharges from oil refineries, coal conversion plants, or municipal waste treatment facilities.
Phenol can be released as a vapour from both natural and man-made sources, especially areas contaminated by phenol-containing substances.
It is naturally present in animal waste and decomposing organic matter.
Phenol is found in:
Humans may be exposed to phenol through:
Phenol is highly irritating to the skin, eyes, and mucous membranes. Acute exposure can result in symptoms such as:
Animal studies show phenol has high acute toxicity, particularly through oral exposure.
Chronic exposure in humans has been linked to:
Skin contact over time can cause inflammation and necrosis. In animals, long-term inhalation has resulted in effects on the nervous system, lungs, heart, liver, and kidneys.
There is no human data regarding reproductive or developmental effects of phenol. However, animal studies have shown:
There is limited evidence linking phenol exposure to cancer in humans. Some studies in occupational settings found small, non-significant increases in certain cancers, though not directly attributed to phenol.
Animal studies have shown:
EPA classification:
Eye Contact:
If phenol gets into the eyes, remove contact lenses if present. Rinse eyes immediately with plenty of water for at least 15 minutes, keeping eyelids open. Cold water may be used. Seek medical attention immediately.
Skin Contact:
In case of skin exposure, flush the affected area with plenty of water for at least 15 minutes while removing contaminated clothing and shoes. Cold water may be used. Apply an emollient to soothe the irritation. Wash clothing and clean shoes before reuse. Get medical attention immediately.
Serious Skin Contact:
Wash thoroughly with disinfectant soap, apply antibacterial cream, and seek immediate medical attention.
Inhalation:
If inhaled, move the individual to fresh air. If the person is not breathing, administer artificial respiration. If breathing is difficult, give oxygen. Seek immediate medical attention.
Serious Inhalation:
Evacuate the person to a safe area. Loosen tight clothing (collar, tie, belt, waistband). If the person is not breathing, perform mouth-to-mouth resuscitation and administer oxygen. Seek medical help immediately.
Ingestion:
If swallowed, do not induce vomiting unless directed by medical personnel. Never give anything by mouth to an unconscious person. Loosen tight clothing. Seek medical attention immediately.
Phenol is combustible at high temperatures and flammable in the presence of open flames or heat. It is not flammable in the presence of shocks, oxidizers, reducers, combustible materials, organic materials, metals, acids, or alkalis.
Use exhaust ventilation or other engineering measures to maintain airborne vapour concentrations below threshold limits. Ensure that eyewash stations and safety showers are accessible near the work area.
The following PPE (personal protective equipment) is recommended when handling phenol:
In case of a large spill, wear:
Note: The recommended protective clothing might not be sufficient in all situations. Consult a specialist before handling phenol to ensure appropriate safety measures are in place.
